The composite of ordered mesoporous carbon (CMK-3) and Li4Ti5O12 (Li4Ti5O12/CMK-3) was prepared by the wet impregnation of CMK-3 with LiNO3 and Ti(OC4H9)4 solution followed by calcination. Its morphology and structure were examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The content of Li4Ti5O12 in the mesoporous nanocomposite was determined by thermogravimetric analysis. Its electrochemical performance as the negative electrode material of lithium-ion batteries was investigated by galvanostatic charge-discharge tests, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The results show that Li4Ti5O12 is formed inside the mesopore channels of CMK-3 and some particles are located on the surface of CMK-3. The composite shows significantly greater high-rate performance than commercial Li4Ti5O12. The specific capacity of Li4Ti5O12 in the composite is higher than Li4Ti5O12 without CMK-3 (117.8 mAh·g-1 at 1C rate), and its stabilized specific capacity reached 160, 143, and 131 mAh·g-1 at 0.5C, 1C, and 5C charge-discharge rates, respectively, with a columbic efficiency of nearly 100%. The capacity loss after 100 cycles at 5C rate was less than 0.62%. This result clearly indicates that CMK-3 improves the high rate performance of Li4Ti5O12, likely by reducing the particle size of Li4Ti5O12 and increasing its electronic conductivity owing to the unique structure and good electronic conduction nature of CMK-3.

Fund: The project was supported by Harbin Science and Technology Innovation Fund for Excellent Academic Leaders, China (2012RFXXG103), Fundamental Research Funds for the Central Universities, China (HEUCFT1205), and Science and Technology Support Program of Jiangsu Province, China (BE2012152).